University of Toronto
Course: MUS 2122H: Music and the Brain - Fall 2008
Instructor: Dr. Lee Bartel
Portfolio: reference, review, reflect and report.
ENTRIES 7 & 8
Five Ways Brain Scans Mislead Us.
by Dr. Michael Shermer
Scientific American: Mind & Brain, November 2008
Music facilitate the neurogenesis, regeneration and repair of neurons.
by Hajime Fukui and Kumiko Toyoshima
Elsevier, Medical Hypotheses, 71:5 (2008): 765-769
B1- SUMMARY OF ARTICLE 7
Dr. Shermer cautions us that the metaphor of a Swiss Army knife (with a collection of specialized modules) employed in the 21st century to help us in understanding and explaining the complex processes of the brain is not quite appropriate, tending to oversimplify the true realities of the physical world. As today’s scientists employ the module metaphor to describe specific regions of the brain while a machine scans it (fMRI), he warns us that these brain scans are misleading, having led us to overemphasize the localization of brain function. Our overreliance on their use gives us a misleading picture of brain operation, so he highlights several flaws of fMRI imaging scanner capabilities.
1. “Unnatural environment for cognition”
a. The fMRI instrument invented to scan inside a brain weighs 12 tons. The huge tube, in which a person’s head must remain still once jammed inside to reduce any head motion, can blur images during the scan.
b. The unnatural environment leaves many feeling claustrophobic and limit participation. The subject sample cannot then be completely random, so it cannot be said to fairly represent all brains.
c. The manner, in which the experiment is conducted, is nowhere close to a real life situation, so the readings provide partial truths.
2. “Scans are indirect measurements of brain activity.”
Popular accounts about fMRI research say that the brain lights up when we think about something when, in fact, it doesn’t. To make an image, “the machine transmits a certain radio-wave frequency, which excites the protons of our brain to match that resonant frequency caused by the magnetic field, and in the process they shed some energy.” This is the energy the machine measures to create the image.
3. “Colors exaggerate the effects in the brain.”
Pictures of the brain’s splotches with sharply defined coloured regions are highly misleading, because they suggest well-defined processing blocks, when, in fact, neural activity may be distributed in more of a loosely defined network.
Furthermore, each module can respond to many things and finally, most brain activity is not stimulus-driven, but spontaneous. Many areas of the brain are continually active during different processing tasks, and separating them out properly is a challenge that requires careful experimental design.
4. “Brain images are statistical compilations.”
During a given experiment, the scanner snaps pictures of rapid-fire brain activity every two seconds. Researchers then combine the data and take averages for the subjects by using statistical software to convert raw data and correct intervening variables. Dr. Shermer reminds us that the image does not represent one person’s brain. It is a rather statistical computation of the entire subject pool rendered with artificial colours to highlight the places where there is a consistent response to a given task or experimental condition.
5. “Brain areas activate for various reasons.”
Interpreting fMRI scans is not a precise science, as it means looking at one spot to try to determine what happens in a brain, which, in fact, an area could be lighting up when involved in all sorts of tasks. For some experiments, this works very well, because decisions provide contrast between tasks. Neuroscientists then have something to compare. The problem resides in showing the difference in emotional tasks, there being both rational and emotional ways of thinking, and every brain area lights up undergoing many different states. There is unfortunately no data to tell us how selectively active an area is.
In conclusion, Dr. Shermer believes that to better map the brain’s neural activity, a better metaphor of a distributed intelligence that more closely matches the network distribution of tasks in the brain is warranted.
B2- SUMMARY OF ARTICLE 8
Fukui and Toyoshima hypothesized that “listening to music facilitates the neurogenesis, the regeneration and repair of cerebral nerves by adjusting the secretion of steroid hormones, in both directions (increase and decrease), ultimately leading to cerebral plasticity. They added that music “affects levels of such steroids as cortisol (C), testosterone (T) and estrogen (E), and … the receptor genes related to these substances, and related protein.”
They discussed how changes in neuron organization caused by steroids have been documented in animal species, as has the relationship between steroids and cerebral plasticity been confirmed in humans. The nervous system is a target for steroids, which regulate important functions like “reproduction, feeding behavior, brain development, neurogenesis, neuroprotection, cognition and memory.” In humans, steroid hormones are involved in spatial perception and cognition (learning and memory). The correlation between musical ability and spatial cognition established, the assumption that some correlation exists between musical ability and steroid hormones appears reasonable. Furthermore, they noted that many studies had documented that musical stimulation also affected various biochemical substances, so listening to music was effective in alleviating and relieving stress, able to reduce cortisol levels and, in other instances, alter levels of testosterone. Other research added that musical activities adjusted steroid secretion in “elderly individuals and … likely to alleviate psychological states such as anxiety and tension.” And finally, steroid levels could either increase or decrease.
They concluded that music listening and playing altered steroid levels, a thesis in agreement with previous studies’ results, which documented strong correlations between steroids and spatial perception, and cognition and the effects of music listening on steroid secretion. The hypothesis that listening to music adjusted the steroid hormone cascade, facilitating the neurogenesis, regeneration and repair of neurons, appeared highly plausible. And with recent research positing the possible involvement of nerve damage in neuropsychiatric disorders, musical activities could enable the protection, repair and even regeneration of human cerebral nerves. Music, they wrote, was a safe, inexpensive and most of all, non invasive therapeutic option which could replace most drugs or hormone replacement therapy presently being used to prevent major diseases such as Alzheimer’s and dementia.
The title of Shermer’s article Five Ways Brain Scans Mislead Us, disturbs our sense of certainty in modern science by questioning the grounds upon which we have come to unconsciously, yet confidently, believe to be standing truths. We have certainly been led to believe that modern technology allows us to understand more about our minds than ever before, and an article that questions its value in finding our answers shifts our attention, not so much about what we know, but how we assume that certain facts are true. On the one hand, assumptions are good. They let us discover an incredibly varied array of new facts and help us seemingly solve the never-ending challenges Mother Nature sends our way. On the other hand, he cautions, the problem arises when one believes our assumptions are the ultimate truths and are immutable when, in fact, we are only observing certain patterns of truths arising from our assumptions and truths can change with different assumptions.
And though new technologies have opened the way to new discoveries, we must remain sceptical, our reality, an ever-evolving process of possibilities, rather than truths. Shermer is teaching us to not be passive learners, but rather engaged learners, using our thinking skills to seek out ways to improve or build upon our present knowledge to achieve a better understanding of the brain’s complexity. He is certainly inviting us to think about how well fMRI works when it needs to measure activities that provide contrasts between tasks, giving neuroscientists something to compare. When it comes to study fluidity, however, complex thoughts and feelings about socially meaningful situations, the system needs improvement, not able to measure subjective experiences. A system that can measure more subtle psychological processes must be developed, but a change in research style must follow to measure more subtle psychological processes. If we wish to restore qualitative evaluation, since judgments depend on quality as well as quantity, we will need to explore a science of qualities, rather than a science of quantities.
Of course, to achieve such a shift in scientific perspective, a lightweight, mobile and inconspicuous brain imaging system that can compile empirical data about our brain states while subjects experience genuine social interaction with real thoughts and feelings in meaningful social situations must be developed. The results will inevitably take into account intrinsic meaning. And can improving present technology also answer the dilemma in mapping gene expression patterns and behaviour? Such an advancement would definitely open up the measurement of psychological complexities, illuminating a much broader range of human experience.
By taking the time to engage in a reflective process to seek out ways to improve present knowledge, a question arises. Will acknowledging qualitative science give rise to a more humane science of the people? The outcome will only be determined by the assumptions we make, letting us draw certain conclusions about what truths and possibilities. And assumptions can be faulty. Fukui and Toyoshima discussed the brain’s plasticity and its ability to change and adapt to new learning throughout life. New assumptions about our potential have initiated research, which is bringing forth once-ignored truths, because it was assumed the brain could not change.
They noted the influx of scientific studies on music as researchers’ interest levels increased, music’s potential being better understood. Can one attribute this to an inability to alleviate stressors by more conventional means? It doesn’t really matter, the point being they found that listening to music could facilitate neurogenesis, and alleviate and relieve stress and other psychological states such as anxiety and tension. And suggesting that music could be of import to the medical system as a therapeutic care option is breathtaking.
There is a certain irony that quantitative science, having discovered the brain’s plasticity, must collaborate with qualitative science. Those first tentative steps, music beginning to receive credibility for its healing capacities in the scientific world, are hard won. Could this change also include a renewed interest in humankind’s conscious inner life? Could this change take on a materialistic society, become selfish and arrogant, trampling its emotional core, functioning only on basic ability and emotion? (One can hope a more evolved human species would include musicality, creativity, imagination and positivity.) Could this be a glimmer into a new century, one that could break down the distinction between the subjective vs. the objective, the self vs. the other, the rational vs. the emotional and art vs. science, embracing the network of intelligences rather than only prioritizing rational intelligence?
Music will help us further understand how developing both the internal and external selves will allow us to extend our range of experience and perhaps attain the ultimate measure of intelligence. Inquiring minds, sceptical minds and visionary minds like Shermer, Fukui and Toyoshima force us to evolve, pushing the boundaries of our beliefs and helping us to transform and adapt, always taking an active part in what kind of human beings we want to be.